This application is based on Japanese Patent Application No. 2000-290363 filed on Sep. 25, 2000, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a rotary electric machine and a method for manufacturing the same.
2. Description of Related Art
JP-A-54-66406 discloses an AC rotary electric machine that has a plurality of coils. The coils are inserted into slots in orderly manner to provide short coil ends by preventing crossings of the coil ends. However, this arrangement forms larger space in the slots to prevent the crossings of the coil ends.
JP-B-2927288 discloses an alternator for vehicle as a rotary electric machine, that has a plurality of segments and a plurality of joining portions between the segments. In this arrangement, a space factor of a stator winding in a slot can be increased. However, it is necessary to handle a lot of segments and to accomplish a complex assembling process.
JP-A-11-299153 discloses an alternator for vehicle that provides uniformly arranged coil ends. However, it is not easy to form all coil ends in a substantially identical manner.
One aspect of the present invention addresses these drawbacks by providing an improved arrangement of a rotary electric machine.
According to a first embodiment of the present invention, a rotary electric machine has a rotor and a stator. The stator has a stator core with a plurality of slots and a stator winding. The slots include a plurality of regular slots and a plurality of irregular slots. The stator winding has a plurality of in-slot portions accommodated in the slots and coil ends. The in-slot portions and the coil ends being arranged to provide a discontinuity of the stator winding at a region where the irregular slots are located.
Since the stator winding has a discontinuity, the stator winding may wound easily. In this arrangement, it is possible to improve a cross-sectional ratio of the conductors to the slot. Furthermore, it is possible to improve productivity by reducing complex manufacturing process.
The stator winding may be assembled by winding the conductors one over another. The irregular slots may be located side by side. The stator winding may have a plurality of conductors for providing the in-slot portions. The stator winding may have no conductor cross over a region where the irregular slots are located. The conductors may be wound one over another.